Control system



y 1946; A. L. ARMENTROUT 2,400,957

CONTROL SYSTEM Filed Sept. 23, l942 2 Sheets-Sheet l '//7 en fo r'drflwrkrmcnfm v j omqg May 28, 1.946. A. L. ARMENTROUT CONTROL SYSTEMFiled Spt. 25, 1942 2 Sheets-Sheet 2 4 m /n reafar Arf/zur 1. ArmenfraufPatented May 28, 1946 UNITED STATES PATENT OFFICE 2,400,967 CONTROLSYSTEM Arthur L. Armentrout, 1m Beach, Calif.

Application September 23, 1942, Serial No. 459,412

11 Claims.

This invention has to do with a control system and relates moreparticularly to a system of controlling and operating a plurality ofunits, as for example, a plurality of engines, electrical generators, orother like units. There are numerous situations in which it is desiredto control or regulate a plurality of individual units. For example inaircraft and in boats it is common to have a number of engines requiringregulation and control. There'are also situations in which a number ofelectrical generators are involved requiring control and regulation.

It is a general object of this invention to pro vide a control systemwhereby a plurality of units, as for example, engines, generators, orthe like, which are individually regulable, are connected to operate insynchronism.

Another object of this invention is to provide a control system forconnecting a plurality of units to operate in synchronism, which systemcontemplates establishing one of the units as the master unit from whichthe several other units are controlled, By the present invention Iprovide a selective control system which makes it possible to select anyone of the several units as the master unit from which the others arecontrolled.

It is another object of this invention to provide a system of thecharacter referred to in which the speed of synchronous operation of theseveral units can be regulated at will. In accordance with the presentinvention provision is made for regulaticnoi the speed of the masterunit which controls the speed of operation of all of the units.

Another object of the invention is to provide a selective control forthe units whereby one or more of the units may be speeded up or sloweddovm with reference to the other units. By the present invention a groupof several units, say for instance, four units, can be divided into twobanks either one of which may be varied with reference to the other.

A iui'ther object of the present invention is to provide a system of thecharacter referred to in which the several units of any one bank areoperated in synchronism. The invention provides for the selection of oneof the several units of a bank as the master unit which establishes thespeed for all of the units of that bank.

The various objects and features of my invention will be best and morefully understood from the following detailed description of a typicalform and application of the invention, throughout which description Irefer to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view illustrating the system of the invention;Fig. 2 is an enlarged detailed fragmentary view illustrating parts ofone of the units of-the system, some parts being shown in section; andFig. 3 is a view showing a switch construction such as may be used incarrying out the invention.

This invention contemplates, generally, the control and regulation of aplurality of units by which the units are made to operate in synchronismor in a predetermined relationship one to the other. The invention isapplicable, generally, to various forms or types of units requiringcontrol and regulation. For example, it may be employed advantageouslyfor the control of engines such, for example, as the several engines ofan aircraft. or it may be applied to the regulation of electricalgenerating units. In the example illustrated the units are electricalgenerat ing units operated by fluid pressure motors and the control orregulation of the units is effected through throttling of the fluidsupply to the motors. I wish it understood, however, that when I referto a unit subject to regulation that I con= template various devices asunits being controlled,

' and I do not wish the invention understood as limited or restricted tothe particular type or form of unit illustrated. The invention may beused to advantage to synchronize internal combustion engines in whichcase the throttle of the engines may be operated by the control system.

In the example of the invention illustrated in the drawings there arefour like units A, C and D subject to regulation and control. Each unitas illustrated'lncludes, generally, an alter nating current powergenerator ill, a iluid motor H for driving the power generator it, anoverrunning clutch l2 driving the power generator it from the motor H, acontrol generator l3 driven by the motor I l, and a throttle valve itcontrolling the flow of operating fluid to the motor Ill.

The several power generators it may be used to energize individualcircuits or they may be conl nected together as circumstances require.In the case illustrated the generators iii are three-phase alternatingcurrent generators and the output from the generators'lt oi units D andC is connected with a common power line L to form what I will term theleft bank of units while the generators III of units E and A areconnected to a common power line l... forming what I will term the rightbank of units, The several units are divided into banks for purposeshereinafter described. However, it will be obvious that all of thegenerators may be connected together to a common power line in whichcase they would form a single bank. Further, the output from eachgenerator Ill may be under control of a switch S so the units can beindividually cut out of the system if desired. A switch S may beprovided for connecting the two banks together.

As a part of the control provided by the present invention each unitincludes an alternating current generator I3 driven by the motor II, apair of alternating current synchronous motors l5 and is operativelyconnected with the throttle valve M of the unit through a differentialmechanism H.

The elements just described and which are best illustrated in Fig. 2 ofthe drawings are so arranged that one pinion l8 of the differentialmechanism is driven by motor l5 while the other pinion H! is driven bymotor IS. The pinions I8 and I9 are connected by planetary gears 2|!carried by a planetary ring 2|. With this arrangement if the alternatingcurrent motors l5 and I6 are operating in opposite directions and at thesame speed all of the motion is taken up in the planetary gears 2|) sothat the planetary ring remains stationary. However, should the speedsof one of thesynchronous motors vary relative to the other there will bemotion of the planetary ring in one direction or the other, dependingupon which of the motors is running fastest. In accordance with theinvention the throttle valve I4 is operated through differential in thespeed or direction of operation of the two motors I5 and IS. Theoperative connection is made by providing the planetary ring 2| withteeth so that it forms a worm gear that meshes with a worm segment 22having a pivotal axis 23. A link 24 connects the segment 22 with thestem of the throttle valve.

The control system provided by the present invention for operating theseveral units in synchronism is an alternating current system whichfunctions so that the alternating current control generator |3 of theunit selected as the master effects control of all of the other .units.The control circuit is preferably a three-phase circuit. For sake ofsimplicity in the drawings I have illustrated a simplified wiringdiagram in which the several lines necessary for carrying thethree-phase circuit are representedby a single line. It will beunderstood of course that in practice there will be a multiplicity ofconductors and connections necessary for handling a three-phasealternating current circuit.

In accordance with the present invention a line 25 connects the controlgenerator |3 of each unit with the synchronous motor IB of that unit,while a line 26 connects the control generator with a terminal of amaster selector switch 21. The control element 23 o! the selector switchis connected to the motors l5 of the several units by a connection 29.The control member 23 of the master selector switch 21 is operable toengage but one terminal connected with a control generator at a time.However, it is operable to connect with the terminal of any of the unitsthat the operator may desire. For instance, in the drawings the controlmember 28 is shown in engagement with the terminal of unit A, that is,the terminal of the switch 21 which is connected with the generator l3of unit A.

With the arrangement thus far described the output from the controlgenerator of each unit is fed to the motor |6 of that unit so that themotor l5, being a synchronous motor, operates at the same speed as thegenerator 13. If the several units are all operating at exactly the samespeed the motors IE will all operate at the same speed. However, theremay be variations in the speed of operation of the several units. Theoutput of the selected control generator l3 being the generator III ofunit A, is carried by the line 26 from the generator [3 of unit A to themaster selector switch 21 where it is distributed by connection 29 tothe motors l5 of the several units. Through this latter connection, thatis, through the connection from the selected control generator l3 all ofthe motors l5 of the units are operated at exactly the same speed,namely, the speed at which the selected control generator is operating.This particular speed will, of course, be exactly the same as that atwhich the motor l6 of unit A is operating, since the generator l3 ofunit A is connected with the motor iii of that unit by the connection25.

If there is any variation in speed of the synchronous motors l5 and I6of any one of the other units that differential in speed will operatethe differential mechanism of that unit which, in turn, will operate thethrottle of that unit through the connection above described, causingthe unit to speed up or slow down, depending upon which motor isoperating faster than the others. The relationship of parts is such thatthe operation of the throttle brings about an adjustment in theoperation of the unit so that its motor comes to the speed of the motorH of the selected unit A. From the foregoing description it will beapparent that the selected unit A will operate constantly under a givenload at whatever speed it has been set to operate, while the other unitswill be automatically adjusted to the unit A.

It may be desired, in practice, to speed up or slow down the operationof the entire system. To accomplish this the present invention providesa speed control means 30 which includes a pair of reversing switches inconnection with each of the units. Each pair of reversing switchesincludes a reversing switch 3| in the connection 25 from the controlgenerator to the motor l8 and a reversing switch 32 in the connection 29from the master selector switch 21 to the motor I5.

In the drawings the two reversing switches 3| and 32 of each unit areshown operable by a common control shaft 33. In fact a common controlshaft is shown in thevmeans 30 carrying the reversing switches of all ofthe units so that a single operating lever 34 of the means 30 on theshaft 33 thereof will simultaneously operate all of the reversingswitches of the means 30.

The reversing switches 3| and 32 are designed and related so that whenthe control lever 34 of the means 30 is thrown in one direction, forinstance, to the left, the switch 3| reverses while the switch 32continues to pass current without reversal, whereas if i the lever 34 isthrown to the right the opposite is true, that is, the switch 32 willreverse, whereas the switch 3| will continue to operate withoutreversal.

My invention is in no way concerned with the details of elements such asthe switches occurring in the system. In Fig. 3 I show an example of amechanism that may be employed for reversing switche such as switches3|.

In Fig, 3 there is illustrated a switch 3| opertionship will continuethroughout able by the shaft 33 so that when the shaft is turned to theleft the switch reverses but if the shaft is turned to the right theswitch contin ues to function without change. The switch may involve apanel 86 to which the line L to be controlled is connected. Wires of theline L are connected to posts 8| and 82 at one side of the panel andposts 8| and 8| at the other side of the panel. The posts 8| and 82 areconnected to fixed contacts 84 and 83, respectively, while the posts 8|and 8| are connected to fixed contacts 84* and 83, respectively. Themovable element of the switch may comprise a cross-like body 85 ofinsulating material having a cross-arm X anda cross-arm Y. Contacts 86and 81 are carried at one end of arm X to cooperate with contacts 84 and83, respectively. Contacts 86 and 89* are carried at the other end ofthe arm X to cooperate with contacts 84 and 83, respectively. Anelectrical connection 88 is provided between contacts 81 and 86 and anelectrical connection 89 is provided between the contacts 86 and 83. Thecontacts 86 and 81 and 86 and 69 are of considerable length in thedirection of movement of body 85. and extensions 90 are provided on theends of the arm X to accommodate the contacts. Contacts 90 and 8| areprovided on one end of arm Y and corresponding contacts 9|] and BI*opposite end of arm Y. An electrical connection s3 is provided betweencontacts 90 and 9|! and an electrical connection 94 is provided betweencontacts 9| and 8|.

With a construction of the general type or character just described whenthe rotating ele ment of the switch is in the position shown in Fig. 3,post 8| is connected with post 8|", while post 82 is connected with post8|, and this relaconsiderable movement of the switch part 65 to theright. The connection will be reversed, however, if the switch element85 is moved a suitable amount to the left. Upon moving the switchelement 85 to the left contacts 90 and flfl will be brought into contactwith contacts 84 and 84* thus connecting posts 8| and 8| while contactsSI and 9| will contact contacts 83 and 83* thus connecting posts 82 and8| This latter arrangement effects a reversal of the connection that isillustrated in Fig. 3.

It is to be understood that when I refer to operation of the control toeffect reversal of the motors I do not necessarily mean that themotorsliterally stop and change direction, but rather it may be that thecontrol is only operated momentarily so that the current is reversed inthe motors causing but slight reduction of speed and not continuing longenough to reverse the direction of motion. Slight or momentary reductionof speed will effect a slight or limited change in speed of the unitsthat are controlled.

With the arrangement of reversing switches above described it will beimmediately apparent that the motor l or the be reversed at will,depending upon the direction in which the control lever 3d of means 30is operated. If the lever 34 is operated to the left, that is to rotatethe shaft 33 to the left, switch 3| will reverse causing reversal ofmotor [6, while the switch 32 will remain without reversal leaving themotor |5 operating in its original direction. With the direction ofrotation of motor I6 reversed the differential mechanism is set inoperation. causing the planetary ring 2| to revolve which in turn causesthe throttle valve of the unit are provided on the motor i6 of a unitcan to be operated. Whether the valve is opened or closed will dependupon which of the motors is reversed.

With the arrangement illustrated, that is, with all of the reversingswitches of the means 30 on the two banks, for instance, it may bedesired to speed up one bank relative to the other, or it may be desiredto speed up one bank while the other'bank is correspondingly sloweddown. .As an example of such operation it may be considered that thepower lines L and L, energized from the units as above described, areconnected to propelling motors driving a ship, the line L energizing thelefthand motor and the line L energizing the righthand motor. Tomaneuver the ship it may be desired to speed up one of the propellingmotors while the other is being slowed down.

To effect the operation just referred to the present invention providesa turning control means 40 and in its preferred form it also providesselector switches M and 42 by which one of the units of each bank canunit with reference to which the other unit or units of the bank aresynchronized. In the arrangement illustrated the selector switch 4|controls the selection of the right bank, that is for units A and B,while the selector switch 42 controls the left bank, or units C and D.

The turning control means 46 in the form illustrated in the drawingsincludes a series of switches on a common operating shaft 43 undercontrol of an operating lever 44. The switches of the'means '36 functionto reverse the motors l5 of one bank while the motors l6 of the otherbank-are reversed and they serve to disconnect Or separate the two banksof units so that they are independentof each other insofar as thecontrol system is concerned. In the drawing the means 40 is shown toinclude a reversing switch 45 in the connection 25 of each unit, that isthe means 40 provides a reversing switch between the generator l3 andthe motor |'6 of each unit. The reversing switches 45 of one bank areset opposite to those of the other bank, that is, the reversing switches45 of the units of the left bank are such that when the control lever 44is thrown to the left the switches do not reverse but continue tooperate normally, whereas the switches 45 of the right bank reversecausing the motors l6 of the right bank to reverse. When the lever 44 isthrown to the right the opposite is true, that is, the switches 35 ofthe left bank reverse, whereas the switches 45 of the right bankcontinue operation without reversal in which case the motors iii of theleft bank are reversed. Through the switches 45 the motors l6 of one ofthe banks of units are reversed whenever the lever 44 is operated ineither direction from the neutral position.

The means to includes a reversing switch 46 in a line 4t connectingswitch 42 and the branch of line 29 leading to the motors l5 of the leftbank, and a reversing switch i! in a line 4! connecting switch ti andthe branch of line 29 leading to the motors is of the right bank. Theswitches 46 and t] are normally in a neutral or disconbe selected as themaster control shaft 43 of means nested position. These switches areoperated by the common operating shaft 43 but are set to operateoppositely and so that when the lever 44 is thrown tothe left bothswitches areengaged, one of them serving to pass the current to its bankwithout reversal while the other reverses the current. For example,switch 46 may pass the current unreversed while switch 41 effects areversal thereof. When the lever 44 is thrown in the opposite directionor to the right the switches operate oppositely, that is, switch 46serves to reverse the current whereas switch 41 makes connection withoutreversal. The switches 46 and 41 are related to the switches 45 so thatwhen the motors l6 of the left bank are reversed by switches 45 themotors are reversed by the switch 41, whereas when the motors i6 of theright bank are reversed by switche the motors l of the left bank arereversed by switch l6.

ii of the right bank The selector switches 4| and 42 are fed from thelines 26 from the control generators of the several units. Extensions 26and 26 extend from the lines 26 from units A and B respectively toterminals of the switch 4|. The control member 50 of the switch ll canbe engaged with either of the terminals. to connect whichever one isdesired with the line A! controlled by switch 41. Through the connectionjust described the control generator of either unit A or B may beselected by means of switch ll as the source of energizing the motors H5or units A and B, the unit selected becoming the control unit to whichthe other unit of the bank is regulated to synchronize.

Branches 26 and 26' from the lines 26 connected with the generators i3of units C and D, respectively, connect with terminals of selectorswitch 62. The control member 62 of the switch 42 may be engaged witheither terminal to connect at either line 46 controlled by switch 46.Through this connection the synchronous control of the units forming theleft bank may be selected as hereinabove described with reference to theright bank When the units are being operated in banks, as Just describedit is necessary that the control connections to the two banks bedisconnected so that controlling current reaches the banks only throughthe selector switches ll and 42 and not through selector switch 21. Forthe purpose of separating the banks a disconnect switch 60 is providedto open the line 28 leading from the master selector switch 21. Adisconnect switch 6| is provided in the portion 29 of line 29 whichextends from switch 60 to the point where line 46 connects the line 26.A disconnect switch 62 is provided in the section 29 of line 26 leadingfrom the switch 6| to the right bank. The cutout switches 60, 6| and 62are all operated by the 40 and are all set so that they are closed whenthe system is operating through the master selector switch 21. When theoperating lever 44 of means 46 is thrown in either direction theswitches 60, ii and 62 all open so that the two banks oi. units aredisconnected insofar as their control through the master selector switch21 is concerned.

In practice the speed control means 30 is normally employed merely forthe purp or varying the speed of the unit set or selected as the masterunit with reference to which all the other units are synchronized. Whenthe means M) is operated to divide the units into two banks, a left bankand a right bank. one of these banks will the various parts of theimmediately accelerate in speed while the other decelerates, dependingupon the direction in which the lever 44 is thrown. I! it is desired toaccelerate or decelerate only one bank, leaving the other operatingunder normal conditions, control lever ll of the means 36' may besimultaneously with the control It or means 66 so that the motors ll ofone bank are reversed to neutralize the eiiect of the control throughthe means lli insofar as the motors of that bank are concerned.

It will be obvious that in carrying out the invention various indicatorsmay be employed in connection with various parts of the system, forinstance, it may be desirable in some installations to provide aninstrument panel at a suitable point, for instance in the vicinity ofthe control members of the control system, and such panel may includevarious indicating instruments, such as tachometers for indicating thespeeds oi! the various units, indicators for showing the positions ofthe throttles of the various units, and various electrical instrumentsshowing the condition of electrical system. In the case of a systemapplied to the several engines of an aircraft it will generally bedesired to provide tachometers in connection with the several mechanismscontrolled and also to provide indicators to show the throttlepositions, in order that the operator may know what power is available.

It will be understood, of course, that various forms or types ofsynchronous motors or electrical units may be employed in carrying outthe invention. For example in some cases it may be desirable to use selfsynchronous apparatus such as is commonly known under the trade name ofSelsyn. Such apparatus involves a transmi corresponding to a generatorll above described and a receiver corresponding to a synchronous motorsuch as either motor I! or ii. When this type of apparatus is used it isnecessary to novide an energizing unit not involved in the arrangement Ihave described in detail.

Having described only a typical preferred iorm and application of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to mysel any variations ormodifications that may appeal to those skilled in the art or fall withinthe W of the following claims.

Having described my invention, I claim:

1. A system for synchronizing two independently, operating unitsincluding, an alternatinl current generator driven by each unit, aocntrd member for each unit, a differential control 101 operating eachcontrol member including a differential gear mechanism connected withthe cmtrol member and a pair of synchronous motor! one driving onepinion of the mechanism and thi other driving the other pinion of themechanism and electrical connecting means whereby the t'l motors oi thecontrol for one unit are energilel by the generator of that unit whilethat generato also energizes one motor of the control for th other unit,while the other motor or the last men tioned control is energized by thegenerator 0 said other unit, the connecting means includin means forreversing the current supplied to on of the motors.

2. A system for synchronizing two independ ently operating unitsincluding, an alternatin current generator driven by each unit, a cart:member for each unit, a dlirerential control 1: operating each controlmember including a dii ierential gear mechanism with ti acoacev controlmember and a pair of synchronous motors, one driving one pinion oi themechanism and the other driving the-other pinion oi the mechanism, andelectrical connecting means whereby the two motors of the control forone unit are energized by the generator of that unit while thatgenerator also energizes one motor 01' the control for the'other unit,while the other motor of the last mentioned control is energized by thegenerator of said other unit, the connecting means including currentreversing means whereby the current supplied to the motors controllingthe first mentioned unit may be reversed to vary the speed of the firstmentioned unit.

3. A system for synchronizing two independently operating unitsincluding, an alternating current generator driven by each unit, acontrol member for operating each control member including adifferential gear mechanism connected with the control member and a pairof synchronous motors, one driving one pinion of the mechanism and theother driving the other pinion of the mechanism, and electricalvconnecting means whereby the two motors of the control for one unit areenergized by the generator of that unit while that generator alsoenergizes one motor of the control for the other unit, while the othermotor of the last mentioned control is energized by the generator ofsaid other unit, the connecting means including a reversingvswitch inconnection with each motor.

4. A system for synchronizing two independently operating unitsincluding, .an alternating current generator driven by each unityacontrol member for each unit, a differential control for operating eachcontrol member including a differential gear mechanism connected withthe control member and a pair of synchronous motors, one driving onepinion of the'mechanism and the other driving the other pinion of themechanism, and electrical connecting means whereby the two motors of thecontrol for one unit are energized by the generator of that unit whilethat generator also energizes one motor of the control for the otherunit, while the other motor or the last mentioned control is energizedby the generator of said other unit, the connecting mean including areversing switch in connection with each motor, and means connecting thereversing switches for each pair of motors so that either one or themotors can be reversed independently of the other.

5. A system for controlling a plurality of indeoperation 01' the severalunits to one unit selected as a master unit, and means. for dividing theunit into two independent banks each-including a. plurality of unitssynchronized to one unit selected as amaster unit. 1 I

6. A system for controlling aplurality oi indeeach unit, a differentialcontrol for pendently operating units including an interconnectionbetween the units for synchronizing the operation of the several unitsto one unit selected as a master unit, and means for dividing the unitsinto two independent banks each inof units synchronized to one masterunit, and including a speed control whereby a diiference in speedobtains between the units of the two banks.

7. A system for controlling a plurality of independently operatingunitsincluding an interconnection between the units including a meansfor selecting one'unit as a master unit to which the other units aresynchronized and means for controlling the speed of operation of themaster unit, and a means for dividing the units into two banks eachhaving a master unit to which the other units of the bank aresynchronized.

8. A system for controlling a plurality of inde pendently Operatingunits including an interconnection between the units including a meansfor.

selecting one unit a a master unit to which-the other units aresynchronized and means for controlling the speed of operation of themaster unit, and a means. for dividing the units into two banks,including a speed control by which either bank can be selected tooperate faster than the other. i

9. A system for controlling a plurality of independently operating unitincluding an interconnection between the units including a means forselecting one unit as a master unit to which the other units aresynchronized and mean for controlling the speed of operation of themaster unit, and a means for dividing the units into two banks,including a speed control by which either bank can be selected'tooperate faster than theother, and a synchronizing control whereby anyunit of a bank can be selected a the master unit of that bank to whichthe other units are synchronized.

10. A system for controlling a plurality of independently operatingunits trical interconnection between the units including a means forselecting one unit as a master unit towhich the other units aresynchronized and means for controlling the speed of operation of themaster unit, and a means for dividing the units into twobanks eachhaving a master unit to which theother units of the bank aresynchronized.

111A system for controlling a plurality of independently operating unitsincluding an interconnection between theunits including a means forselecting one unit 'as .a master unit to which the other units aresynchronized and means for controlling the speed of operation or themaster unit, and tin electrical circuit for dividing the units into twobanks each having a master unit to which the-other units orthe bank aresynchronized.

ARTHUR L.

including an elec-

